sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy

{
  "id": "59f550a4bba5977414b3162d6d7f878f3e27ce22c7d87d4650e98c466a47b1b2",
  "url": "https://osv.dev/vulnerability/CVE-2025-21636",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.probe_interval' is used.",
    "evidence": "osv:CVE-2025-21636",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.177",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.125",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.72",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-21636",
      "aliases": [
        "CVE-2025-21636"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "d1e462a7a5f359cbb9a0e8fbfafcfb6657034105"
                },
                {
                  "fixed": "1dc5da6c4178f3e4b95c631418f72de9f86c0449"
                },
                {
                  "fixed": "44ee8635922b6eb940faddb961a8347c6857d722"
                },
                {
                  "fixed": "284a221f8fa503628432c7bb5108277c688c6ffa"
                },
                {
                  "fixed": "bcf8c60074e81ed2ac2d35130917175a3949c917"
                },
                {
                  "fixed": "6259d2484d0ceff42245d1f09cc8cb6ee72d847a"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21636.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.14.0"
                },
                {
                  "fixed": "5.15.177"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "5.16.0"
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                {
                  "fixed": "6.1.125"
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            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.2.0"
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                  "fixed": "6.6.72"
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            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21636.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.513525658Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1dc5da6c4178f3e4b95c631418f72de9f86c0449",
        "https://git.kernel.org/stable/c/284a221f8fa503628432c7bb5108277c688c6ffa",
        "https://git.kernel.org/stable/c/44ee8635922b6eb940faddb961a8347c6857d722",
        "https://git.kernel.org/stable/c/6259d2484d0ceff42245d1f09cc8cb6ee72d847a",
        "https://git.kernel.org/stable/c/bcf8c60074e81ed2ac2d35130917175a3949c917",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21636.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-21636",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21636.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-21636",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517713,
  "published_at": "2025-01-19T10:17:54.576+00:00"
}